Purpose: Previous research has demonstrated positive effects of oligochromatic light on wounds including faster healing, altered gene expression patterns and changes in mitochondrial enzyme activity. This study was created to investigate whether light therapy's association with faster healing is the result of a local or systemic effect.

Methods and Materials: 48 ICR mice were divided into 3 groups of 16. Two groups received a unilateral wound via 8mm punch biopsy to the flank under general anesthesia, while the third group received bilateral wounds. The experimental groups were then exposed to oligochromatic light provided by a light-emitting diode (LED) array producing light at 670nm at an intensity of 50mW/cm2 and fluence of 4J/cm2. One unilateral wound group received no light as a control, while the other unilateral group did. The bilateral wound group had only one side exposed to light. Wounds were inspected daily and measured on day seven to assess the number of days until healed.

Summary: Statistical comparisons of wound size at day 7 post-biopsy yielded no statistically significant difference between control groups and those receiving treatment. Analysis of groups regarding average days needed to complete healing was not statistically significant, although there was a trend toward significantly increased wound healing rate when comparing the treated vs untreated wounds of bilaterally wounded mice.

Conclusion: LED light did not show any definitive effect on wound healing in this study contrary to previous reports using similar methods. There was a trend towards faster final healing in the treated groups, which was statistically insignificant. The trend towards increased healing in treated vs untreated wounds of bilaterally wounded mice may indicate a local-only effect of treatment and should warrant further investigation.